The present invention relates generally to medical equipment and more particularly to ultrasonic methods and devices which may be utilized to a) cardiovascular obstructions such as athroscloratic plaque or thrombus located in a mammalian blood vessel and b) to deliver an infusion of one or more therapeutic agents or drugs concurrently with ultrasonic energy so that the dissemination, dispersal, distribution, absorption, activity or duration of effected by the ultrasonic energy.
A number of ultrasonic devices have heretofore been proposed for use in ablating or removing obstructive material from anatomical structures, such as blood vessels. Examples of devices which purportedly utilize ultrasonic energy, alone or in conjunction with other treatment modalities, to remove obstructions from anatomical structures include those described in U.S. Pat. No. 3,433,226 (Boyd), U.S. Pat. No. 3,823,717 (Pohlman, et al.), U.S. Pat. No. 4,808,153 (Parisi), U.S. Pat. No. 4,936,281 (Stasz), U.S. Pat. No. 3,565,062 (Kuris), U.S. Pat. No. 4,924,863 (Sterzer), U.S. Pat. No. 4,870,953 (Don Michael, et al.), U.S. Pat. No. 4,920,954 (Alliger, et al.), and U.S. Pat. No. 5,100,423 (Fearnot) as well as other patent publications WO87-05739 (Cooper), WO89-06515 (Bernstein, et al.), WO90-0130 (Sonic Needle Corp.), EP316789 (Don Michael, et al.), DE3,821,836 (Schubert) and DE2,438,648 (Pohlman).
Ultrasound transmitting catheters have been utilized to successfully ablate various types of obstructions from blood vessels of humans and animals. Patients who are candidates for ultrasound ablation of vascular obstructions may also be candidates for treatment by various thrombolytic agents (i.e., blood clot dissolving agents) or other therapeutic agents or drugs.
Many types of therapeutic agents or drugs may be delivered by the ultrasonic catheter of the present invention. The types of agents or drugs which may be utilized in cardiovascular applications of the catheter include, but are not necessarily limited to, the following:
i. Thrombolytic Agents
Examples of thrombolytic agents utilized to dissolve thrombotic material include: streptokinase (Streptokinase for Infusion, Astra Pharmaceutical Products, Inc., Westboro, Mass., and Kabikinase(trademark), Kabi Pharmacia, Piscataway, N.J.); urokinase (Abbokinase(trademark), Abbott Laboratories, North Chicago, Ill.); and tissue plasminogen activator (TPA). Such agents are administered intravascularly following myocardial infarction or other cardio vascular events wherein a thrombus is suspected to be in formation or in existence.
ii. Anticoagulant Agents
Examples of anticoagulant agents utilized to prevent the subsequent formation of thrombus or blood clots include heparin (Heparin Sodium Injection, Wyeth-Ayerst Laboratories Philadelphia, Pa.).
In patients who are undergoing ultrasonic angioplasty procedures wherein a vascular obstruction is ablated by way of ultrasonic vibration, the administration of one or more therapeutic agents or drugs may be indicated before, during or after ultrasonic ablative procedure. Thus, it is desirable to design an ultrasonic ablation catheter through which various therapeutic agents or drugs may be delivered.
Additionally, it is desirable to design and devise new catheter devices for concurrently delivering a flow of liquid medicament along with ultrasonic vibration such that the distribution, delivery, absorption and/or efficacy of the medicament may be improved or enhanced by the ultrasonic vibration.
The present invention provides improved ultrasound delivery catheters which incorporate means for infusing liquid medicaments (e.g., drugs or therapeutic agents) concurrently or in conjunction with the delivery of ultrasonic energy. The delivery of the ultrasonic energy through the catheter concurrently with the infusion of a liquid medicament will aid in rapidly dispersing, disseminating, distributing or atomizing the medicament. Additionally, it is postulated that the infusion of at least some types of liquid medicaments concurrently with the delivery of ultrasonic energy may result in improved or enhanced activity of the medicament due to a) improved absorption or passage of the medicament into the target tissue or matter and/or b) enhanced effectiveness of the medicament upon the target tissue or matter (e.g., thrombus) due to the concomitant action of the ultrasonic energy on the target tissue or matter.
Further in accordance with the invention, there are provided methods for treating various diseases or conditions by administering therapeutic agents or drugs concurrently or in conjunction with the delivery of ultrasonic energy.
Further objects and advantages of the invention will become apparent to those skilled in the art upon reading and understanding of the detailed description set forth herebelow, and consideration of the accompanying drawings.